Violet acid dye.



UNITED STATES PATENT OFFTCE.

HEIN RICH POLIKIER, OF BERLIN, GERMANY, ASSIGNOR TO AGTIEN-GESELL SCHAFT FI IR ANILIN FABRIKATION, OF SAME PLACE.

VIOLET ACID DYE.

SPEOIFECATTON forming part of Letters Patent No. 684,457, dated October 15, 1901.

Application filed June 10, 1901- Serial No. 64,003. (No specimens) I To call whom, it may concern:

Be it known that I, HEINRICH POLTKIER, of Berlin, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in the Production of Violet Acid Dye; and I do hereby declare that the followingis afull, clear, and exact description thereof, which will enable others skilled in the art to which it appertains to make and use the same.

It is known that derivatives of diphenylbeta-naphthylmethane, owing to the fact that they contain a beta-naphthyl group, are easily converted by sulfonizing agents into new sulfonated dyestuffs remarkable for the purity and intensity of the tints they produce. On the other hand, until now it has been accepted that the corresponding derivatives of diphenyl alpha naphthylmethane do not yield any technically valuable products when similarly treated I have now discovered that the derivatives of diphenyl-alpha-naphthylmethane obtained by condensing tetraalkyl-diamido-benzophenone with methylphenyl alpha naphthylamin can be sulfonated without difficulty and are thus transformed into acid dyestuffs which dye wool a remarkably pure and intense violet.

To further illustrate my invention, I give the following example: Twenty parts of the dyestuft obtained by condensing tetra methyldiamido-benzophenone with methylphenylalpha-naphthylamin,the so-called Victoriablue 4 R, are introduced into eighty parts of fuming sulfuric acid containing thirty per cent. of anhydride, care being taken that the temperature does not essentially exceed 20 centigrade. The mixture is then heated to 35 centigrade and kept at this temperature for about one hour until a test portion is found to dissolve completely in dilute ammonia. The liquid is now poured on ice, and the product after it has been separated by filtration is redissolved in water containing the equimolecular proportion of sodium carbonate, whereupon the sodium salt of the new sulfonic acid is precipitated. It forms in the dry state a red-violet powder easily soluble in water or alcohol to clear red-violet solutions. Its aqueous solution is precipitated by diluted hydrochloric acid, this pre cipitate, however, redissolving in an excess of the reagent to a green, or if the excess employed had. been a large one to a yellowishbrown, solution. On the addition of caustic soda lye the coloration of the aqueous solution changes to a somewhat-dull blue. dyestuff dissolves easily in concentrated sulfuric acid to an orange-brown solution,which on gradual dilution with ice-water assumes a yellowish-brown, green, green-blue, and finally clear-blue coloration. It dyes wool clear-violet shades.

Having thus described my invention and in' what manner the same is to be performed, What I claim is--- The new acid dye belonging to the diphenyl-' naphthylmethane series, said dyestuff being a sulfonic acid of the condensation product obtained from tetraalkyldiamido-benzophcnone and methylphenyl-alpha-naphthylamin, represented by the formula:

R meaning an alkyl group, said dye forming in the dry state a red-violet powder, easily soluble in water or alcohol to red-violet solutions; the aqueous solution being precipitated by diluted hydrochloric acid, this pre cipitate however redissolving in an excess of the reagent to a green, or, if the excess employed had been a large one, to a yellowishbrown solution, the coloration of the aqueous solution changing to a somewhat-dull blue on the addition of caustic-soda lye; the dye dissolving easily in concentrated sulfuric acid to an orange-brown solution which on gradual dilution with ice-water gets yellowish brown, green-blue and finally clear blue; the dye producing on wool clear-violet shades, of great intensity.

The 

